1. Field of the Invention
An increasing variety of methods for detecting analytes are being developed, where most of the methods rely upon only a few different labels. These labels for the most part are radioactive nuclides, enzymes and fluorescers. Each of the labels brings to the assays advantages and problems associated with sensitivity, reproducibility, and interference resulting from components in the analyte sample. Frequently, when confronted within reproducible results or lack of correlation with other techniques, one of the major problems is determining the reason for the lack of correlation. Even after one has been able to isolate the reason for the interference, the solution to the problem may also be significantly complex.
2. Description of the Prior Art
Enzyme Immunoassay, ed, Edward T. Maggio, CRC Press, Boca Raton, Fla., 1980, U.S. Pat. Nos. 3,817,837, 3,875,011 and 4,091,613 are illustrative of enzyme immunoassays which produce nicotinamide adenine dinucleotide(NAD)-reduced form (NADH).